chromeos: Makes AshTestBase/Helper target mash when appropriate

ash/mus/accelerators/accelerator_controller_registrar_test_api.h

-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef ASH_MUS_ACCELERATORS_ACCELERATOR_CONTROLLER_REGISTRAR_TEST_API_H_
-#define ASH_MUS_ACCELERATORS_ACCELERATOR_CONTROLLER_REGISTRAR_TEST_API_H_
-
-#include "base/macros.h"
-
-namespace ui {
-class Accelerator;
-}
-
-namespace ash {
-namespace mus {
-
-class AcceleratorControllerRegistrarTestApi {
- public:
-  AcceleratorControllerRegistrarTestApi();
-  ~AcceleratorControllerRegistrarTestApi();
-
-  // Sends |accelerator| to AcceleratorControllerRegistrar for the pre phase,
-  // and if the pre phase does not process the event the post phase as well.
-  void ProcessAccelerator(const ui::Accelerator& accelerator);
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(AcceleratorControllerRegistrarTestApi);
-};
-
-}  // namespace mus
-}  // namespace ash
-
-#endif  // ASH_MUS_ACCELERATORS_ACCELERATOR_CONTROLLER_REGISTRAR_TEST_API_H_